From owner-freebsd-fs@FreeBSD.ORG Wed Apr 27 05:46:21 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6F7F9106564A; Wed, 27 Apr 2011 05:46:21 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from mail-gx0-f182.google.com (mail-gx0-f182.google.com [209.85.161.182]) by mx1.freebsd.org (Postfix) with ESMTP id E8E8A8FC0C; Wed, 27 Apr 2011 05:46:20 +0000 (UTC) Received: by gxk28 with SMTP id 28so628557gxk.13 for ; Tue, 26 Apr 2011 22:46:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=boNt9t5J57VAh4jZnc6m9oIM5rALCalUSTyNBJPoYjo=; b=v7xK5xpvS47BBzwozLyogvycXmwfkTSj47zazbequoBZ9wrAQvu62EZOv6zvQm+P9q uXYQlMWpdP2ETl53NiK1Qpz9TWDLyv/Wv08eyIjQVBKVEOwM8nSNdFchLbkvQQV0/bXI CUw6rPloJk20IbUEo5OB8QnjIb64P/SF95v84= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=aCYeMyQWGyfnTUUrVUQP8HMl63EnjDvrlpabjnAHNICnXJLoNDDlDZSAw6ig+7DRVu M0aCNobjWe4N+cT85z3qjC4rVHDc4ITHdr0IQoXhRlFqaNd9vJkG8FzihJlCFjB22Ufl jK2+ORAL00baFGIwzy+3JgdZm8dbhmB+hmL1k= MIME-Version: 1.0 Received: by 10.91.164.27 with SMTP id r27mr1523607ago.204.1303883180062; Tue, 26 Apr 2011 22:46:20 -0700 (PDT) Received: by 10.90.70.18 with HTTP; Tue, 26 Apr 2011 22:46:20 -0700 (PDT) In-Reply-To: <4DB759A1.4050201@FreeBSD.org> References: <4DB70949.6090104@FreeBSD.org> <20110426182017.GA92471@freebsd.org> <4DB70F13.6060002@FreeBSD.org> <4DB759A1.4050201@FreeBSD.org> Date: Tue, 26 Apr 2011 22:46:20 -0700 Message-ID: From: Freddie Cash To: Doug Barton Content-Type: text/plain; charset=UTF-8 Cc: freebsd-fs@freebsd.org, Alexander Motin , Alexander Best Subject: Re: Why not just name the cam-ata devices the same as the old names? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Apr 2011 05:46:21 -0000 On Tue, Apr 26, 2011 at 4:47 PM, Doug Barton wrote: > On 04/26/2011 16:04, Mikael Fridh wrote: >> >> Are labels such a perilous affair that you can't just start >> recommending them and/or default to them? > > As far as I can tell, yes. We have various different tools that do different > things, all calling themselves "labels" which don't all work together well. > It's also unclear how many (if any) of those solutions will survive the file > system being newfs'ed. This is where labelling *disks* is the better route. Filesystems come and go, but the disks don't change very often. This is one the nicest things about using FreeBSD systems (all the GEOM stacking and labelling). The only issue I've come across is that GPT stores the secondary header in the last physical sector of the *disk* and not the last physical sector of the GEOM provider, so you end up with spurious "errors" when using labelled disks, gmirror'd labels, and GPT-partitioned mirrors. :( If that one issue was resolved, than a glabel'd disk would be the perfect solution. (going from memory) glabel label mydisk0 da0 glabel label mydisk1 da1 gmirror label label/mydisk0 gm0 gmirror add label/mydisk1 gm0 gpart -s GPT mirror/gm0 Doesn't matter where you move the disks in the system, everything "just works" (with that one "error" message about the secondary GPT label). -- Freddie Cash fjwcash@gmail.com